Monday, August 29, 2016

Importing CSV/TSV data: Tableau example

From now on, charte.ca allows you to import flat comma- or tab-separated data. Usually, CSV/TSV data is just a set of samples that are nor suitable for displaying in a Pie, Bar or Line charts. To overcome this limitation, powerful software packages offer additional functionality like Excel pivot tables. charte.ca allows you to build a pivot table in a few easy steps.

This example shows how you can import data from a Public Tableau visualization. Fortunately, Tableau has a CSV export feature and we will take advantage of it.

1. Login to charte.ca and create a new Regular Line chart.

2. In the Data panel, click "Import" (you can find it right under the data grid).

Please note that pivot tables make sense only for Pie, Bar, or Line charts. Scatter or Bubble charts are based on flat data, so there is no need to perform this pivot table magic.

You have probably noticed that this example does not involve any aggregation: every series/category pair in the flat data points to only one value. If this is not the case, and our flat data samples have to be grouped, aggregate function should be used. But this is a good subject for a separate discussion.